Persistent Reservation

Persistent Reservation

[djshetty]

Hi,

I had a doubt. In order to persist the reservation we need to store some
information like reservation keys, scope, type of reservation etc.

Where exactly are such information stored and by whom ?

Regards,
Dhiraj
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RE: Persistent Reservation

[Jansen, Frank]

Dhiraj,

In the most common case, persistent reservations are stored with the
device, such as the storage array.  Note that not all devices
implement/support persistent reservations and there are cases where the
reservations are stored elsewhere, which tends to be the approach in
virtualizing environments.

Regards,

Frank

> -----Original Message-----
> From: linux-scsi-owner@vger.kernel.org 
> [mailto:linux-scsi-owner@vger.kernel.org] On Behalf Of djshetty
> Sent: Thursday, November 16, 2006 7:27 AM
> To: linux-scsi@vger.kernel.org
> Subject: Persistent Reservation
> 
> 
> Hi,
> 
> I had a doubt. In order to persist the reservation we need to 
> store some information like reservation keys, scope, type of 
> reservation etc.
> 
> Where exactly are such information stored and by whom ?
> 
> Regards,
> Dhiraj
> --
> View this message in context: 
> http://www.nabble.com/Persistent-Reservation-tf2642680.html#a7376789
> Sent from the linux-scsi mailing list archive at Nabble.com.
> 
> -
> To unsubscribe from this list: send the line "unsubscribe 
> linux-scsi" in the body of a message to 
> majordomo@vger.kernel.org More majordomo info at  
> http://vger.kernel.org/majordomo-info.html
> 

Re: Persistent Reservation

[Douglas Gilbert]

Jansen, Frank wrote:
> Dhiraj,
> 
> In the most common case, persistent reservations are stored with the
> device, such as the storage array.  Note that not all devices
> implement/support persistent reservations and there are cases where the
> reservations are stored elsewhere, which tends to be the approach in
> virtualizing environments.

The linux SCSI subsystem doesn't interact with lu
persistent reservations. Last time I looked, the
kernel was pretty noisy when a RESERVATION CONFLICT
status was received, even via a sg device node.

You can manipulate persistent reservations from the
user space with sg_persist in sg3_utils package.

Device support for persistent reservations is improving,
Fujitsu SCSI disks have had it for some time. I
noticed that the Seagate 15K.5 series support those
commands while the 15K.4 series and earlier didn't.

Doug Gilbert

>> -----Original Message-----
>> From: linux-scsi-owner@vger.kernel.org 
>> [mailto:linux-scsi-owner@vger.kernel.org] On Behalf Of djshetty
>> Sent: Thursday, November 16, 2006 7:27 AM
>> To: linux-scsi@vger.kernel.org
>> Subject: Persistent Reservation
>>
>>
>> Hi,
>>
>> I had a doubt. In order to persist the reservation we need to 
>> store some information like reservation keys, scope, type of 
>> reservation etc.
>>
>> Where exactly are such information stored and by whom ?
>>
>> Regards,
>> Dhiraj
>> --
>> View this message in context: 
>> http://www.nabble.com/Persistent-Reservation-tf2642680.html#a7376789
>> Sent from the linux-scsi mailing list archive at Nabble.com.
>>
>> -
>> To unsubscribe from this list: send the line "unsubscribe 
>> linux-scsi" in the body of a message to 
>> majordomo@vger.kernel.org More majordomo info at  
>> http://vger.kernel.org/majordomo-info.html
>>
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